The present invention relates to suitcase trucks, and relates more particularly to the retractable handle assembly of a suitcase truck which comprises a mounting base fixed to a suitcase, two sleeves fixed to the mounting base, two retracting tubes inserted into the sleeves, each retracting tube having a first pin hole and a second pin hole, two locking devices mounted in an opening on the mounting base, each locking device having an outward pin for insertion into the first pin hole of second pin hole of one retracting tube to lock the retracting tubes in the retracted or extended position, a control button, and spring-supported link means connected between the control button and the locking devices, whereby when the control button is moved forwards, the locking devices are pulled inwards by the spring-supported link means to disconnect the respective pins from the first or second pin holes of the retracting tubes for permitting the retracting tubes to be moved between the retracted position and the extended position.
Regular utility trucks are commonly made of metal. These utility trucks are convenient in use for carrying luggage. However these utility trucks need much storage space when they are not used, because they are commonly not collapsible. There is known a suitcase truck having a retractable handle. The retractable handle can be collapsed into a retracted position when it is not in use. This structure of retractable handle comprises a sleeve fixedly secured to the suitcase, a retracting tube slidably inserted into the sleeve, and a springy retainer fixedly secured to retracting tube, the springy retainer having a raised portion forced into one retaining hole of the sleeve to hold the retracting tube in the extended portion or the retracted position. When to move the retracting tube between the extended position and the retracted position, the raised portion of the retainer must be forced inwards from the respective retaining hole on the sleeve. During the operation, the user's fingers tend to be injured.